Thomas Aquinas

“ Reason is shown to be so much the more perfect, according as it is able to overcome or endure more easily the weakness of the body and of the lower powers. And therefore human virtue, which is attributed to reason, is said to be "made perfect in infirmity," not of the reason indeed, but of the body and of the lower powers. ”

“ This is the sense of the words, "which God works in us without us." As to those things which are done by us, God causes them in us, yet not without action on our part, for He works in every will and in every nature. ”

“ Therefore human virtues are habits.
Reply to Objection 1: Sometimes we give the name of a virtue to that to which the virtue is directed, namely, either to its object, or to its act: for instance, we give the name Faith, to that which we believe, or to the act of believing, as also to the habit by which we believe. When therefore we say that "virtue is the limit of power," virtue is taken for the object of virtue. For the furthest point to which a power can reach, is said to be its virtue ”

“ But health and beauty are not operative habits. Therefore neither is virtue.
Objection 2: Further, in natural things we find virtue not only in reference to act, but also in reference to being: as is clear from the Philosopher (De Coelo i) , since some have a virtue to be always, while some have a virtue to be not always, but at some definite time. Now as natural virtue is in natural things, so is human virtue in rational beings. Therefore also human virtue is referred not only to act, but also to being. ”

“ But goodness does not seem to be good, as neither is whiteness white. It is therefore unsuitable to describe virtue as a "good quality."
Objection 2: Further, no difference is more common than its genus; since it is that which divides the genus. But good is more common than quality, since it is convertible with being. Therefore "good" should not be put in the definition of virtue, as a difference of quality.
Objection 3: Further, as Augustine says (De Trin. xii, 3) : "When we come across anything that is not common to us and the beasts of the field, it is something appertaining to the mind." ”

“ In this way therefore virtue is applied to evil things: so that the "virtue" of sin is said to be law, in so far as occasionally sin is aggravated through the law, so as to attain to the limit of its possibility. ”

“ Mode of action follows on the disposition of the agent: for such as a thing is, such is its act. And therefore, since virtue is the principle of some kind of operation, there must needs pre-exist in the operator in respect of virtue some corresponding disposition. ”

“ The body, indeed, man has in common with other animals; and the same is to be said of the forces which are common to the soul and body: and only those forces which are proper to the soul, namely, the rational forces, belong to man alone. ”

“ Art. 2 - Whether human virtue is an operative habit? Objection 1: It would seem that it is not essential to human virtue to be an operative habit. For Tully says (Tuscul. iv) that as health and beauty belong to the body, so virtue belongs to the soul. ”

“ But this is not the case with specific forms, as whiteness and health; for everything that we apprehend, is not apprehended with the notion of white and healthy. We must, however, observe that, as accidents and non-subsistent forms are called beings, not as if they themselves had being, but because things are by them ”